Dual to Single mod
10-15-2007, 05:42 PM
#23
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From what I understand, on a dual exhaust, when the pipes splits, the 2 pipes are smaller in diameter then the main pipe. A 60mm dual might split into a 55 mm pipe. So if you cut one side off, then you would be restricting yourself even more. But that's only if the pipes go smaller.
10-15-2007, 06:02 PM
#24
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It keeps your car from sounding all crazy. a straight through resonator free exhaust = that crazy loud weedwacker you here driving around from time to time with civic badges on it.
10-15-2007, 06:13 PM
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thats an interesting point you bring up...from what i can see on the exhaust, it looks like i might be able to keep it pretty close to 60 mm. it may not look pretty, but it will be wrapped so i wont be able to see it lol
10-15-2007, 06:14 PM
#26
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Originally Posted by ridestrt,Oct 15 2007, 06:02 PM
It keeps your car from sounding all crazy. a straight through resonator free exhaust = that crazy loud weedwacker you here driving around from time to time with civic badges on it.
note to self...resonator good, civic whacker bad
10-15-2007, 08:24 PM
#27
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It depends on the overall design of the exhaust. It would be safe to say in most causes resonator= good. I wouldn't test it personally, you don't want to sound like you're cutting grass . It isn't restrictive and it keeps the sound reasonable.
10-15-2007, 09:14 PM
#28
Originally Posted by mister x,Oct 11 2007, 12:39 PM
I'd carefully cut one leg of the dual at a straight part of the pipe, with a Dremel preferably to get a very clean cut. Then instead of welding, use a cap which is clamped on to see if it works. If it doesn't, should be easier to go back to dual. BTW, I think you'll find the section you capped will act like a Helmholtz resonator and reduce some drone.
Also for the arguement about a 63mm being best for N/A, I now have a t1r 70mm sparrow and have no signs of lost power
10-16-2007, 09:45 AM
#29
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Originally Posted by TJF,Oct 12 2007, 11:13 AM
Most of the motors we built were for Pro Stock drag racing, Super Stock drag racing, or Hooters Cup.
It is like variable valve timing, you need different amounts of flow to make maximum horsepower at different RPMs. Since we cant change the size of the runner or valve during operation, and the motors we built didnt have variable timing, the answer is to control flow with runner length and diameter (you might call it "an exhaust system").
You cannot trade one for the other. Horsepower is a made up number that is simply a mathmatical factor of torque... if you give up one, you give up the other.
It is like variable valve timing, you need different amounts of flow to make maximum horsepower at different RPMs. Since we cant change the size of the runner or valve during operation, and the motors we built didnt have variable timing, the answer is to control flow with runner length and diameter (you might call it "an exhaust system").
You cannot trade one for the other. Horsepower is a made up number that is simply a mathmatical factor of torque... if you give up one, you give up the other.
Take a SB2 or whatever for a given track. The intake, cam, and exhaust is tuned for peak hp at 9000 rpm say. You get LESS HP if you add any more backpressure. Period. The engine is optimized for that rpm and flow.
If you are changing rpm all the time and you don't have variable components designed after 1955, then you look at the area under the curve and identify what will give you the best speed over the track. Sometimes that does require lowering the HP peak with a flow restriction to get more area under the torque curve. (yes, I do know it is a mathematical calculation Tq x rpm/5252, lol)
10-16-2007, 10:13 AM
#30
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Originally Posted by nitewing117,Oct 15 2007, 09:14 PM
I tried doing that with my apexi WS2 and i lost a lot more power than I thought to the point where even the transition to VTEC felt like my car was bogging. I may have lost less power if I didnt just cap off one side like that, but I never tried it.
Also for the arguement about a 63mm being best for N/A, I now have a t1r 70mm sparrow and have no signs of lost power
Also for the arguement about a 63mm being best for N/A, I now have a t1r 70mm sparrow and have no signs of lost power